I had this strange humming noise after swapping in a B16A2 into my 96 Coupe. I finally found the source of the noise. It was the IAC, or Idle Air Controller. I figure hey, I will replace it and call it a day. So I picked up a salvaged unit and even plugged it into my car while it was running to confirm operation and no noise. All checked out. I get home remove the IAC and replace it with the one I just bought. I fire the car up and the noise/hum continues. I am dumb-founded.

First, does anyone know why the IAC solenoid would hum? Second, how can I fix my problem. I would just assume drop the $130 for a new OE IAC, but I am afraid to hook it up out of fear that it will "break" too.

 

3 wire or 2 wire?

 

Per Chilton, the M/T is 2-wire and A/T is 3-wire. I will need to double check, but is should be 2-wire, as I used a 97 M/T EX Civic harness for the swap, BUT my car was an automatic to start with and I converted it. I have confirmed voltage (~12.8v) via voltmeter.

 

....does the hum go away when the IACV isn't mounted to the IM?

 

i'll check that one out.